Variable area fan nozzle with bypass flow

ABSTRACT

The exit area of a nozzle assembly is varied by translating a ring assembly located at a rear of the engine nacelle. The ring may be axially translatable along the axis of the engine. As the ring translates, the trailing edge of the ring defines a variable nozzle exit area. Translation of the ring creates an upstream exit at a leading edge of the ring assembly. The upstream exit can be used to bleed or otherwise spill flow excess from the engine bypass duct. As the engine operates in various flight conditions, the ring can be translated to obtain lower fan pressure ratios and thereby increase the efficiency of the engine. Fairings partially enclose actuator components for reduced drag.

TECHNICAL FIELD

The present invention generally relates to gas turbine aircraft engines,and in particular, to a translating trailing edge variable area nozzleassembly for a gas turbine aircraft engine for controlling the air flowexhausted from the engine for varying performance output.

BACKGROUND

Typical aircraft turbofan jet engines include a fan that draws anddirects a flow of air into and around an engine core and a nacelle. Thenacelle surrounds the engine core and helps promote the laminar flow ofair past the engine core. The flow of air that is directed into theengine core is initially passed through a compressor that increases theair flow pressure, and then through a combustor where the air is mixedwith fuel and ignited. The combustion of the fuel and air mixture causesa series of turbine blades at the rear of the engine core to rotate, andin turn to provide power to the fan. The high-pressure heated exhaustgases from the combustion of the fuel and air mixture are thereafterdirected through an exhaust nozzle out of the rear of the engine.

The flow of air that is directed around the engine core is called bypassflow and provides the main thrust for the aircraft. The bypass flow alsois used to help slow an aircraft, when the flow is diverted by thrustreversers mounted in the nacelle structure that surrounds the enginecore. The bypass flow may or may not be mixed with the engine coreexhaust before exiting.

Several turbofan engine parameters are important to those of skill inthe art in order to optimize design characteristics and performance. Thebypass ratio (BPR) is the ratio of air mass passing through the fan tothat going through the core. Higher BPR engines can be more efficientand quieter. In general, a higher BPR results in lower average exhaustvelocities and less jet noise at equivalent thrust rating of a lower BPRengine. Also, the exit area and mass flow rates and pressures define thefan pressure ratio (FPR).

Turbofan engine operation parameters and characteristics can further bereflected in a turbofan engine's operating map. Operation maps can becreated in various ways, such as on turbine rig test results orpredicted by applicable computer programs as is known in the art.Typical turbine operation maps can show relationships between pressureratios (e.g., FPR) on the y-axis and corrected mass flows on the x-axis.The operation line(s) on the turbofan operation map reflects the line orranges in which the relationship between FPRs and correct mass flowvalues result in maximum thrust and minimum fuel consumption. Forexample, it is known that altering the engine's characteristics thatlower the operating line can increase fuel efficiency and reduce noiseemissions from the engine since more thrust is produced with less fuelbeing injected into the combustors, and the stoichiometry of the engineis increased. The resulting reduction of FPRs, however, can reach apractical limit as a low FPR can cause engine fan stall, blade flutteror compressor surge under certain operating conditions, withinsufficient bypass flow possibly causing engine malfunction.

A solution to optimizing the operating line at all flight conditions,for those engines that draw significant benefit from such anoptimization, includes varying the exit nozzle area during operation.Variable area nozzles for aircraft jet engines are known to helpaircraft obtain lower FPR by favorably reconfiguring engine cyclecharacteristics. Such variable area nozzles generally have included aseries of flow deflectors or fins (often called “turkey feathers”) thatcan flair outwardly or pivot inwardly to increase or decrease the sizeof the nozzle opening and accordingly expand or constrict the flow ofthe exhaust air upon exit. Unfortunately, the expansion of such turkeyfeathers may cause undesirable leakage and can adversely interact withthe outside air flow passing over the engine, which can createundesirable drag, noise, and a reduction in thrust due to the overboardleakage, leading to greater fuel consumption. In addition, priorvariable area nozzle systems typically have been heavy, expensive andsomewhat complex in their structure and operation, generally requiringthe coordinated movement of multiple components that employ complicateddrive mechanisms.

Accordingly, it can be seen that a need exists for a variable areanozzle assembly for an aircraft turbine engine that promotes a costeffective, simple and efficient operation for control of engine outputto match desired flight conditions.

SUMMARY

According to one embodiment of the invention, the exit area of a nozzleassembly is varied by translating, or moving fore and aft, a ringassembly located at the rear of the engine nacelle. The ring may beaxially translatable, for example, along the axis of the engine. As thering translates, the trailing edge of the ring defines a variable nozzleexit area. Translation of the ring creates an upstream exit at a leadingedge of the ring assembly to bleed or otherwise spill excess flow fromthe engine bypass duct. As the engine operates in various flightconditions, the ring can be translated to optimize on-demand the engineoperating line, resulting in lower fan pressure ratios and therebyincrease the efficiency of the engine.

The foregoing and other features, aspects, and advantages of theinvention will become more apparent upon review of the detaileddescription of the preferred embodiments set forth below when taken inconjunction with the accompanying drawing figures, which are brieflydescribed as follows.

DESCRIPTION OF THE DRAWINGS

According to common practice, the various features of the drawingsdiscussed below are not necessarily drawn to scale. Dimensions ofvarious features and elements in the drawings may be expanded or reducedto more clearly illustrate the embodiments of the invention.

FIG. 1 illustrates an aircraft engine having a trailing edge variablearea nozzle assembly according to a first embodiment of the invention.

FIG. 2 is a partially schematic section view of the aircraft engineaccording to the first embodiment.

FIG. 3 is an end view of the nozzle end of the engine according to thefirst embodiment.

FIG. 4 is a partially schematic section view of the variable area nozzleassembly portion according to the first embodiment.

FIG. 5 is another partially schematic section view of the variable areanozzle assembly according to the first embodiment.

FIG. 6 is a partially schematic, exploded section view of the variablearea nozzle assembly according to the first embodiment.

FIG. 7 is a partially schematic isolated view of a guide structure ofthe variable area nozzle assembly according to the first embodiment.

FIG. 8 is a partially schematic section view of the variable area nozzleassembly according to the first embodiment.

FIG. 9A is a partial exploded view of a variable area nozzle assemblyaccording to a second embodiment of the invention.

FIG. 9B is another partial exploded view of the variable area nozzleassembly according to the second embodiment.

FIG. 10 is another partial exploded view of the variable area nozzleassembly according to the second embodiment.

FIG. 11 is another partial exploded view of the variable area nozzleassembly according to the second embodiment

FIG. 12 is another partial exploded view of the variable area nozzleassembly according to the second embodiment.

FIG. 13 is a partial exploded view of a variable area nozzle assemblyaccording to a third embodiment of the invention.

FIG. 14 is an isolated view of a guide structure of the variable areanozzle assembly according to the third embodiment.

FIG. 15 is schematic illustration of an actuation system for thevariable area nozzle assembly according to the third embodiment

FIG. 16 is an isolated view of a stabilizer of the variable area nozzleassembly according to the third embodiment.

FIG. 17 is a section view of the variable area nozzle assembly accordingto the third embodiment.

FIG. 18 is another section view of the variable area nozzle assemblyaccording to the third embodiment.

FIG. 19 is another section view of the variable area nozzle assemblyaccording to the third embodiment.

FIG. 20 is another section view of the variable area nozzle assemblyaccording to the third embodiment.

FIG. 21 is a partial exploded view of a variable area nozzle assemblyaccording to a fourth embodiment of the invention.

FIG. 22 is an isolated view of a guide structure of the variable areanozzle assembly according to the fourth embodiment.

FIG. 23 is a section view of the variable area nozzle assembly accordingto the fourth embodiment.

FIG. 24 is another section view of the variable area nozzle assemblyaccording to the fourth embodiment.

FIG. 25 is another section view of the variable area nozzle assemblyaccording to the fourth embodiment.

FIG. 26 is another section view of the variable area nozzle assemblyaccording to the fourth embodiment.

FIG. 27 is a partial exploded view of an actuator for a variable areanozzle assembly according to a fifth embodiment of the invention.

FIG. 28 is schematic illustration of an actuation system for thevariable area nozzle assembly according to the fifth embodiment.

FIGS. 29A-29C illustrate the actuator according to the fifth embodimentof the invention in various modes of operation.

FIG. 30 is a section view of the variable area nozzle assembly accordingto the fifth embodiment.

FIG. 31 is another section view of the variable area nozzle assemblyaccording to the fifth embodiment.

DETAILED DESCRIPTION

FIGS. 1-8 show a variable area nozzle assembly according to a firstembodiment of this invention.

Referring to FIGS. 1 and 2, the engine 10 includes a trailing edgevariable area fan nozzle (VAFN) assembly 12 having a translating ringassembly 50 that may be adjusted, for example, as the engine 10 operatesunder varying flight conditions. As stated, such an adjustment can causea shift in the engine's operating line. The translating ring assembly 50is translated (i.e., moved fore and aft) to vary the nozzle exit area inorder to optimize engine operation and to adjust an amount of enginebypass flow spilled through an upstream exit in the nozzle assembly 12.By bleeding or spilling off excess fan flow through the upstream exit ofthe nozzle assembly 12, lower fan pressure ratios for the same amount ofdelivered mass flow can be obtained, thereby increasing stall marginsand avoiding engine malfunction and shutdown. For the purposes ofillustration, the exemplary variable area fan nozzle assembly 12 of thepresent invention is shown in the context of a gas turbine jet aircraftengine. The engine 10 may be mounted to a wing or fuselage of anaircraft, for example, by a pylon or other, similar support (notillustrated).

The engine 10 includes an engine core 16 and a nacelle 18. The enginecore 16 is housed in a core cowl 19. As shown in FIG. 2, a fan 20 ismounted adjacent to an upstream end of the nacelle 18, and includes aseries of fan blades 22 that are rotated about the engine centerlineC_(L) during engine operation so as to draw a flow of air into an inletend 26 of the engine 10. An annular bypass duct 24 is defined betweenthe engine core 16 and the nacelle 18. The air flow drawn into theengine 10 is accelerated by the rotating fan blades 22. A portion of theair flow is directed into and through a compressor (not illustrated)within the engine core 16. The air flow through the engine core 16 isinitially passed through the compressor to increase the air flowpressure, after which the pressurized air is passed through a combustor(not shown), where it is mixed with fuel and ignited. The combustion ofthe fuel and air mixture within the combustor causes the air to expandwhich in turn drives a series of turbines at the rear of the engine,indicated generally at 38, to rotate and in turn to provide power to thefan 20.

The bypass flow accelerated by the rotating fan blades 22 passes throughthe bypass duct 24, past stators 40, and out through the nozzle assembly12. The bypass flow provides the main engine thrust. The high pressureheated exhaust gases from the combustion of the fuel and air mixture aredirected through the nozzle assembly 12 out of the rear of the enginecore 16.

The translating ring assembly 50 can be a ring-like annular airfoilstructure mounted at the trailing end of a thrust reverser 80, adjacentto and circumscribing the engine core cowl 19. The area between thetrailing edge of the ring assembly 50 and the core cowl 19 defines thenozzle exit area 52 for the nozzle assembly 12. As shown in FIGS. 1 and3, the ring assembly 50 can comprise an arcuate first ring section 54and an arcuate second ring section 56, each ring section 54, 56 beingaxially translatable in the direction of the bidirectional arrow 58.Translation of the ring assembly 50 effects a desired size of anupstream exit 60 and varies the outlet geometric and exit area 52 of thenozzle 12 outlet for the engine bypass flow. The ring assembly 50 can betranslated, for example, by a plurality of ring actuators 70.

The thrust reverser 80 may be adjacent to and forward of the translatingring assembly 50 to block and redirect the bypass flow in the bypassduct 24 into a thrust reversing vector. In FIG. 1, the thrust reverser80 and the translating ring assembly 50 are in stowed or closedpositions. The thrust reverser 80 can comprise an arcuate first sleeveor cowl section 82 and an opposed arcuate second sleeve or cowl section84 (shown in FIG. 3). The thrust reverser sleeve sections 82, 84 can beaxially translatable in the direction of the bidirectional arrow 86 by aplurality of sleeve actuators 90. The thrust reverser sleeve sections82, 84 are translatable over a series of cascade vanes 88. The cascadevanes 88 are indicated by dashed lead lines in FIG. 1 because they arenot visible when the thrust reverser 80 is in the stowed position. Axialtranslation of the sleeve sections 82, 84 in the fore and aft directionsallows the bypass air flow to be passed through the cascade vanes 88 togenerate a thrust-reversing vector.

FIG. 3 is a partial section view of the aft end of the engine 10, andillustrates the arrangement of the ring and sleeve actuators 70, 90,respectively, around the periphery of the engine 10. As shown in FIG. 1,and more clearly in FIG. 3, the sleeve half section 82 and the ringhalf-section 54 cooperate to generally define an approximately 180degree sector of the combined thrust reverser and translating ringstructure. Likewise, sleeve half section 84 and ring half section 56cooperate to generally define an opposed approximately 180 degree sectorof the thrust reverser and translating ring structure. Together, theseapproximate 180 degree sectors cooperate to define the entireapproximate 360 degree thrust reverser-translating ring structure.

In the embodiment shown in FIGS. 1-3, each thrust reverser sleevehalf-section 82, 84 of the thrust reverser 80 can be translatable by oneor more (three are shown) peripherally spaced sleeve actuators 90fixedly mounted in the nacelle 18. In the embodiment shown, threeactuators 90 are used for each sleeve half-section 82, 84. Eachhalf-section 54, 56 of the translating ring assembly 50 similarly can betranslated by one or more (three are shown) peripherally spaced ringactuators 70. Ring actuators 70 can be mounted on an adjacent thrustreverser sleeve section 82, 84, respectively. The ring actuators 70could be powered by, for example, electricity, mechanical, pneumatics,hydraulics, or other means, with appropriate power cables and conduits(not shown) passing via pre-defined passages between or above the thrustreverser cascade boxes or pivot doors. The number and arrangement ofring and sleeve actuators 70, 90 may be varied, for example, accordingto the thrust reverser and ring assembly configuration, and according toother factors. The ring sections 54, 56 may be mounted in, for example,upper and lower guide structures 102 located at each end ofcorresponding sleeve sections 82, 84, respectively. FIG. 7 is anisolated view of a guide structure 102. Guide tubes 104 may be mountedin the nacelle 18 and may extend into the ring sections 54, 56 tostabilize the sections 54, 56 against undesirable translation and/orvibration. Guide tubes may alternatively be mounted in the thrustreverser 80.

The translating ring assembly 50 may be a continuous (e.g., one-piece)or, as shown in FIG. 3, a continuing (e.g., split or multi-section)generally annular ring having an airfoil cross section. The upstreamexit 60 (formed when the ring assembly 50 moves in the aft directionaway from the sleeve sections 82, 84) therefore can have the form of agenerally annular gap extending around the perimeter of the rear of thenacelle 18. Other outlet shapes can also be used, e.g., oval, etc. Thegenerally annular gap between the ring sections 54, 56 and the sleevesections 82, 84 can be continuous, for example, or interrupted at one ormore locations, such as, for example, at points of bifurcation or otherseparation of the ring assembly 50. The bypass duct 24 may also beinterrupted at one or more locations.

The translating ring assembly 50 and surrounding structure are describedbelow with reference to FIGS. 4-7. In FIGS. 4-7, elements that areobscured or partially obscured due to intervening elements are indicatedby dashed lead lines.

FIG. 4 is a partial view of the mounting structure for a first ringsection 54 of the translating ring assembly 50 and the corresponding,adjacent first sleeve section 82 of the thrust reverser 80. The secondring section 56 of the translating ring assembly 50 and the secondsleeve section 84 of the thrust reverser 80, which are shown in FIGS. 1and 3, can be mounted in a similar manner. In FIG. 4, the thrustreverser 80 is in a stowed position, covering the cascade vanes 88. Thetranslating ring assembly 50 is in an open or deployed position so thatan upstream exit 60 is defined between the first ring section 54 and thefirst sleeve section 84. The rearward axial translation of the firstring section 54 to the deployed position is indicated by the arrow A.The ring actuators 70 can extend from the sleeve section 82, across theupstream exit 60, and connect to a fore end of the ring section 54. Theguide tubes 104 can also extend from the sleeve section 82, across theupstream exit 60, and connect to the fore end of the ring section 54. Asleeve actuation cable 96 can connect to each sleeve actuator 90 forpower and to provide simultaneous actuation of each actuator 90.

FIG. 5 shows the thrust reverser 80 in a deployed position and thetranslating ring assembly 50 in the open position. The rearward axialtranslation of the first sleeve section 82 from the position shown inFIG. 4 to the deployed position is indicated by the arrow B. Rearwardtranslation of the sleeve section 82 exposes the cascade vanes 88 duringoperation of the thrust reverser 80. The ring section 54 can also betranslated rearwardly during operation of the thrust reverser 80, asshown in this embodiment. Translation of the ring section 54 at the sametime that the thrust reverser 80 is deployed, may be optional becausethe bypass flow is rerouted through the cascade vanes 88.

FIG. 6 is a partial, exploded view with the first sleeve section 82 andits corresponding first ring section 54, illustrated separate from thesurrounding mounting structure.

FIG. 7 is a partial section isolated view taken through one of the guidestructures 102. Referring generally to FIGS. 3 and 6 and particularly toFIG. 7, in the guide structure 102, a beam 106 can be fixedly attachedto a transverse bulkhead 110 that extends 180 degrees and can includeaxially (e.g., parallel to the centerline of the engine 10) extendingguide tracks 108 attached thereto. The bulkhead 110 may be integral withor otherwise fixedly mounted to the engine nacelle 18 (FIG. 1). Thethrust reverser sleeve section 82 can be connected to axially extendingtrack bars 114 (FIG. 7) that are slidably received within the guidetracks 108 of the fixed beam 106. The thrust reverser sleeve section 82is thereby slidably mounted with respect to the nacelle 18. The thrustreverser sleeve section 82 can also include an axially extending trackguide 116 in which a translating ring track bar 120 is slidablyreceived. The translating ring track bar 120 can be connected to thefirst ring section 54, and the ring section 54 axially translates as thetrack bar 120 slides within the track guide 116. The ring section 54 isthereby slidably mounted with respect to the sleeve section 82 of thethrust reverser 80. The translating sleeve section 82 and the track bar120 can be powered through conventional means, such as mechanical,electric, hydraulic or pneumatic or other equivalent means.

FIG. 8 illustrates one method of operating the ring section 54 toachieve flow diversion in accordance with this invention. For example,the size of the upstream exit 60 and the nozzle exit area 52 can bevaried in order to achieve differing engine operating parameters. Inthis capacity, the upstream exit 60 essentially acts as a “bleed” exitthat spills airflow traveling through the bypass duct 24. FIG. 8 shows apartial section of a downstream portion of the nozzle assembly 12illustrating a portion of the bypass air flow, indicated by the curvedarrows, being bled through the annular upstream exit 60 in one mode ofoperation of the nozzle assembly 12. In FIG. 8, the first ring section54 of the ring 50 and the first sleeve section 82 of the thrust reverser80 are shown in section, along with associated ring and sleeve actuators70, 90, respectively, used for axial translation of the sections 54, 82.The second ring section 56 may be similarly constructed and arrangedwith respect to the second sleeve section 84. The thrust reverser 80 caninclude blocker doors 134 that are operatively coupled to the firstsleeve section 82 and are pivotable in the direction of the curved arrow136 thereby to block and redirect the bypass flow into a thrustreversing vector.

Still referring to FIG. 8, a high pressure seal 130 may be disposedbetween the sections 82, 54, at the trailing edge of the translatingsleeve section 82. In certain modes of operation, when the sections 82,54 are drawn together, the seal 130 can operate to substantially sealany gap between the sections 82, 54 and thereby close the upstream exit60.

As previously discussed, the ring and sleeve actuators 90, 70 can be,for example, mechanical, hydraulic, pneumatic or electric actuators. Inthe illustrated embodiment, the ring actuator 70 is a constant openingair spring damper with hydraulic closing override, and the sleeveactuator 90 is an electric actuator.

FIGS. 9A-12 illustrate a variable area nozzle assembly 212 according toa second embodiment of the invention. The nozzle assembly 212 may bemounted to a nacelle as generally illustrated in FIG. 1, however with nointervening thrust reverser. Therefore, elements within the embodimentshown in FIG. 9A-12 that are analogous to elements in FIGS. 1-8 use asimilar reference numbering system, but are preceded by a “2” or “3.”

FIGS. 9A and 9B are partial cutaway illustrations of the variable areanozzle assembly 212 according to the second embodiment of the invention.In the cutaway illustrations, an outer duct structural liner 214 of thenacelle is visible. The nozzle assembly 212 includes a translating ringassembly (removed for ease of illustration and not shown in

FIGS. 9A and 9B) comprised of two ring sections, of which one ringsection 254 is illustrated in FIGS. 9A and 9B. In FIG. 9A, the ringsection 254 is in the closed (i.e., axially fore) position, and FIG. 9Billustrates the ring section 254 in the open or deployed (i.e., axiallyaft) position.

The ring section 254 can be mounted at the aft end of an engine.Peripherally spaced translating ring actuators 270 may be mounted to abulkhead 310 that is fixedly mounted to the nacelle. Guide tubes 304 mayalso be fixedly mounted to the bulkhead 310 at one end, and received inthe ring section 254 at their opposite ends. The translating ringactuators 270 can act in unison to translate the ring section 254 in thedirection of the bidirectional arrow 258. Referring to FIG. 9B, actuatorshafts 272 of the ring actuators 270 can pass through a blister fairing320 located fore of the ring section 254. Upstream fairings 324 may beprovided at the points where the actuator shafts 272 pass through theblister fairing 320 in order to reduce drag induced by the actuators270. Similarly, downstream fairings 328 may be provided at the pointswhere the actuator shafts 272 are received in the ring section 254.

The ends of the ring section 254 can terminate at beaver tail splitfairings 330. As shown in FIGS. 10 and 11, each end of the blisterfairing 320 can include an upstream portion 332 of a beaver tail splitfairing 330, and a downstream portion 334 of the fairing 330 can beconnected to and translatable with the translating ring section 254.Translation of the translating ring section 254 in the direction of thebidirectional arrow 258 can create an upstream exit 260 between thetranslating ring section 254 and the blister fairing 320. The aft edgeof the blister fairing 320 can include a bullnose section 255 (FIG. 11)to also aid in improving air flow out of upstream exit 260 and minimizeflow disruption caused by linkages supporting the actuator shafts 272.FIG. 12 is a partial, isolated view of the upstream and downstreamfairings 324, 328 of the beaver tail split fairing 330.

The fairings 320, 324, 328, 330 of the aforesaid described embodimentcan by selectively used in conjunction with other embodiments describedherein. By way of non-limiting example, fairings analogous to fairings324, 328 could be used in conjunction with the translating sleeveactuators 90, spaced ring actuators 70, or other actuators disclosedherein.

FIGS. 13-20 illustrate a variable area nozzle assembly 412 according toa third embodiment of the invention. The nozzle assembly 412 includes atranslating ring assembly 450 and may be mounted to a nacelle 18 asgenerally illustrated in FIG. 1. Referring to FIGS. 13 and 14, thetranslating ring assembly 450 according to the third embodiment can becomprised of two ring sections, of which a first ring section 454 isillustrated in FIG. 13. The second ring section 456, illustratedschematically in FIG. 15, may be a mirror image of the ring section 454.

In FIG. 13, the translating ring section 454 is in the closed ornon-deployed position, with no upstream exit defined between the ringsection 454 and the thrust reverser sleeve section 482. The translatingring assembly 450 is mounted aft of a thrust reverser 460 comprising twotranslating sleeve sections, of which a first sleeve section 462 isillustrated in FIG. 13. The first sleeve section 462 of the thrustreverser 460 can be translated by one or more actuators 464. The ringsection 454 can be operated by an actuation system including ringactuators 470 located at each end of the first translating ring section454. Stabilizer assemblies 480 connecting the first ring section 454 tothe first sleeve section 462 can be spaced along the periphery of thenozzle assembly 412 to reduce undesirable translation and/or vibration(e.g., flutter) of the ring section 454. Analogous stabilizer assembliescan be added to other embodiments shown herein where additionalstabilization is desired.

Still referring to FIG. 13, a motor or drive mechanism 482 governs themotion of the ring actuators 470. The drive mechanism 482 is connectedto a splined coupling 484 by transmission shafting 485 and a gear box486. The splined coupling 484 terminates at the aft end of the sleevesection 462 at a gear box 488, which is coupled to flexible cableshafting 490. The flexible shafting 490 is connected to the actuators470 at each end of the translating ring section 454. The drive mechanism482 is thereby coupled to the ring actuators 470 to effect translationof the ring section 454.

The translating ring section 454 may be mounted in, for example, upperand lower guide structures 500 located at each end of the ring section454. Each translating ring actuator 470 can be operably coupled with aguide structure 500, as discussed below with reference to FIG. 14.

FIG. 14 is a partial view of a guide 500 and associated actuator 470 atone end of the ring section 454. The thrust reverser sleeve section 462forward of the ring section 454 can be connected to an axially extendingbeam 502 of the guide 500. The ring section 454 is mounted to a trackbar 503 that is slidably mounted on the beam 502. The ring section 454is thereby slidably mounted with respect to the sleeve section 462. Theguide 500 includes a slider 504 that receives a screw shaft 506. Thescrew shaft 506 can be coupled to a gear box 508 that converts rotarymovement of the flexible actuator cable 490 to rotary movement of thescrew shaft 506. Rotation of the screw shaft 506 within the slider 504translates the track 503 along the beam 502, which can be used to effecttranslation of the ring section 454 in the direction of thebidirectional arrow 458. The aforesaid described actuator system couldbe used in each of the actuator embodiments discussed elsewhere herein.

FIG. 15 is a schematic view of an actuation and control system that maybe used to actuate translation of the translating ring assembly 450illustrated in FIGS. 13 and 14. Referring specifically to FIG. 15 andalso to FIGS. 13 and 14, the drive unit 482 can include a motor 516coupled to a gear box 520. Rotational motion provided by the motor 516is sequentially transmitted through the gear box 520, the transmissionshafting 485, the gear boxes 486, the splined couplings 484, theactuator cable 490, and ultimately to the ring actuators 470 through thegear boxes 488 to provide axial translation of the ring sections 454,456.

Referring to FIG. 15, the motor 516 can be coupled to a host controllerunit 526, which is coupled to a full authority digital engine controller(FADEC) 540. The FADEC 540 can thereby control actuation of the ringsections 454, 456 of the translating ring assembly 450. The FADEC 540can also control actuation of a thrust reverser. Linear variabledifferential transformers 550 can be coupled to the ring sections 454,456 to provide position feedback to the FADEC 540.

FIG. 16 is an isolated view of a stabilizer assembly 480. The stabilizerassembly 480 can include an aft portion 580 fixedly mounted to thetranslating ring section 454, and a guide portion 582 fixed to thetranslating sleeve 482 of the thrust reverser 480. The aft portion 580can be axially slidable within the guide portion 582 with relatively lowclearance to minimize unwanted translation and/or vibration (e.g.,flutter) of the ring section 454.

FIG. 17 is a sectional partial view of a downstream portion of thenozzle assembly 412, taken along a longitudinal section that passesthrough a stabilizer assembly 480. The translating ring section 454 inFIG. 17 is translatable in the direction of the bidirectional arrow 458to create an upstream exit forward of the section 454, as discussedabove with reference to the embodiment illustrated in FIG. 8. Blockerdoors 586 are operatively coupled to the first sleeve section 462 andpivotable in the direction of the curved arrow 588 thereby to block andredirect the bypass flow through cascade vanes 590 to produce a thrustreversing vector.

FIG. 18 is a sectional partial view of a downstream portion of thenozzle assembly 412, taken along a longitudinal section that passesthrough a translating ring actuator 470 at one end of the translatingring section 454.

FIG. 19 is a sectional partial view of a downstream portion of thenozzle assembly 412, taken along a longitudinal section that passesthrough an actuator 464 of the thrust reverser 460.

FIG. 20 is a sectional partial view of a downstream portion of thenozzle assembly 412, taken along a longitudinal section that passesthrough a splined coupling 484.

FIGS. 21-26 illustrate a variable area nozzle assembly 612 according toa fourth embodiment of the invention. The nozzle assembly 612 may bemounted to a nacelle as generally illustrated in FIG. 1.

FIG. 21 is a partially exploded, cutaway illustration of the variablearea nozzle assembly 612, which has a translating ring assembly 650 atan aft end of the nozzle assembly. FIG. 22 is an isolated view of anactuator of the translating ring assembly 650. Translation of thetranslating ring assembly 650 can be effected by an actuation systemsuch as, for example, the actuation system illustrated in FIG. 15.Referring to FIGS. 21 and 22, the translating ring assembly 650 can becomprised of two ring sections, of which a first ring section 654 isillustrated in FIG. 21. The second ring section (not illustrated) may bea mirror image of the ring section 654.

In FIG. 21, the first translating ring section 654 is in the closedposition, with no upstream exit defined forward of the first section654. The ring assembly 650 is mounted aft of a thrust reverser 660comprising two translating sleeve sections, of which a first sleevesection 662 is illustrated in FIG. 21. The translating sleeve section662 of the thrust reverser 660 can be translated by one or moreactuators 664. The ring section 654 can be operated by an actuationsystem including actuators 670 located at each end of the ring section654. Stabilizer assemblies 680 connecting the ring section 654 to thesleeve section 662 can be spaced along the periphery of the nozzleassembly 612 to reduce undesirable translation and/or vibration (e.g.,flutter) of the ring section 654.

Still referring to FIG. 21, a motor or drive mechanism 682 governs themotion of the ring actuators 670. The drive mechanism 682 is connectedto a splined coupling 684 by transmission shafting 685 and a gear box686. The splined coupling 684 terminates at the aft end of the sleevesection 662 at a gear box 688, which is coupled to flexible cableshafting 690. The flexible cable shafting 690 is connected to the ringactuators 670 at each end of the translating ring section 654. The drivemechanism 682 is thereby coupled to the ring actuators 670 to effecttranslation of the ring section 654. The ring section 654 may betranslatably mounted in, for example, upper and lower guide structures700 located at each end of the ring section 654. Each actuator 670 canbe operably coupled with a guide structure 700, as discussed below withreference to FIG. 22.

FIG. 22 is a partial view of a guide 700 and associated actuator 670 atone end of the ring section 654. The translating sleeve section 662forward of the ring section 654 can be connected to an axially extendingbeam 702 of the guide 700. The ring section 654 is mounted to a trackbar 703 that is slidably mounted on the beam 702. The first translatingring section 654 is thereby slidably mounted with respect to the firstthrust reverser sleeve section 662. The ring actuator 670 is coupled atone end to a gear box 708 and at its opposite end to the track bar 703.The gear box 708 utilizes rotational motion of the flexible cable 690 tocause the actuator 670 to translate the ring section 654 in thedirection of the bidirectional arrow 658.

FIG. 23 is a sectional partial view of a downstream portion of thenozzle assembly 612, taken along a longitudinal section that passesthrough one of the stabilizer assemblies 680. The translating ringsection 654 illustrated in FIG. 23 is translatable in the direction ofthe bidirectional arrow 658 to create an upstream exit forward of thesection 654, as discussed above with reference to the embodimentillustrated in FIG. 8. The thrust reverser 660 can include blocker doors786 that are operatively coupled to the first sleeve section 662 and arepivotable in the direction of the curved arrow 788 thereby to block andredirect the bypass flow through variable depth cascade vanes 790 toproduce a thrust reversing vector.

FIG. 24 is a sectional partial view of a downstream portion of thenozzle assembly 612, taken along a longitudinal section that passesthrough an actuator 670 at one end of the translating ring section 654.

FIG. 25 is a sectional partial view of a downstream portion of thenozzle assembly 612, taken along a longitudinal section that passesthrough an actuator 664 of the thrust reverser 660.

FIG. 26 is a sectional partial view of a downstream portion of thenozzle assembly 612, taken along a longitudinal section that passesthrough a splined coupling 684.

FIGS. 27-31 illustrate an actuator 870 for translating ring sections854, 856 of a translating ring assembly 650 (illustrated schematicallyin FIG. 28) according to a fifth embodiment of the invention. Eachtranslating ring section 854, 856 can include an actuator 870 at eachend of the ring section. In FIG. 27, an actuator 870 is shown in acutaway section of a portion of a variable area nozzle assembly 812. Thevariable area nozzle assembly 812 includes a thrust reverser 860 locatedforward of the translating ring assembly 650. The movable cowl or sleeveof the thrust reverser 860 is present but not shown in FIG. 27 for easeof illustration so that that cascade vanes 990 of the thrust reverserare visible. The translating ring assembly 650 and thrust reverser 860of the nozzle assembly 812 can be, for example, generally similar instructure to those of the variable area nozzle assemblies 412, 612discussed above. In FIG. 27, the thrust reverser 860 is in the stowed ornon-deployed position.

Referring to FIG. 27, the translating ring actuator 870 can include abearing 886 that can be fixedly mounted forward of the thrust reverser860. In the embodiment shown, the bearing 886 is coupled to anextensible shaft 888. The shaft 888 is coupled to a spline bush gimbal890, which is coupled to a sliding spline 894. The sliding spline 894 isfixed to a track bar 903, which can be fixed to one end of thetranslating ring section 854 (FIG. 28). The track bar 903 is slidablymounted on a beam 702 that is fixed to a section of the thrust reverser860. The first translating ring section 854 is thereby slidably mountedwith respect to the thrust reverser 860. The bearing 886 at each end ofthe translating ring section 854 is coupled to transmission shafting885. Rotation of the transmission shafting 885 effects translation ofthe ring section 854.

FIG. 28 is a schematic view of an actuation and control system that maybe used with the translating ring assembly 850. Referring specificallyto FIG. 28 and also to FIG. 27, a drive unit 882 can include a motor 916coupled to a gear box 920. Rotation provided by the motor 916 istransmitted through the gear box 920 to the transmission shafting 885.The rotational motion from the transmission shafting 885 is utilized bythe actuators 870 at each end of the ring sections 854, 856 to translatethe ring sections.

The motor 916 can be coupled to a host controller unit 926, which iscoupled to a full authority digital engine controller (FADEC) 940. TheFADEC 940 can thereby control actuation of the translating ring sections854, 856 of the translating ring assembly 850. The FADEC 940 can alsocontrol actuation of a thrust reverser. Linear variable differentialtransformers 950 can be coupled to the ring sections 854, 856 to provideposition feedback information to the FADEC 940.

FIGS. 29A-29C illustrate an actuator 870 in three operational modes. InFIG. 29A, the actuator 890 is fully retracted, corresponding to anoperating condition in which the translating ring assembly 850 and thethrust reverser 860 are stowed. In FIG. 29B, the actuator 890 is in adeployed state in which the translating ring assembly 850 is deployedand the thrust reverser 860 is stowed. FIG. 29C illustrates the actuator890 where the thrust reverser 860 is deployed.

FIG. 30 is a sectional partial view of a downstream portion of thenozzle assembly 812, taken along a longitudinal section that passesthrough an actuator 870 at one end of the translating ring section 854.The translating ring section 854 is in a stowed position in FIG. 30.

FIG. 31 is a sectional partial view of a downstream portion of thenozzle assembly 812, taken along a longitudinal section that passesthrough an actuator 870 at one end of the translating ring section 854.The translating ring section 854 is in a deployed position in FIG. 31.

It will be understood by those skilled in the art that while theforegoing has been described with reference to preferred embodiments andfeatures, various modifications, variations, changes and additions canbe made thereto without departing from the spirit and scope of theinvention. The optional elements in each of the embodiments may beemployed with all possible combinations of other disclosed elements toform additional embodiments.

1. A nacelle for a turbofan engine comprising: (a) a stationary forwardnacelle portion (18); (b) a thrust reverser (80) comprising: (i) anarray of cascade vanes (88) disposed aft of the forward nacelle portion(18); (ii) a thrust reverser sleeve (82, 84) disposed all of the forwardnacelle portion, the thrust reverser sleeve (82, 84) being selectivelymovable between a stowed position and a deployed position, wherein inthe stowed position the thrust reverser sleeve (82, 84) substantiallycovers the cascade vanes (88), and in the deployed position, at least aportion of the cascade vanes (88) are not covered by the thrust reversersleeve; (iii) a plurality of thrust reverser sleeve actuators (90)configured to selectively move the thrust reverser sleeve (82, 84)between the stowed position and the deployed position; (c) a fan nozzlesleeve (50) disposed aft of the thrust reverser sleeve (82, 84) andbeing selectively movable between a forward position and one or moreextended positions, wherein an upstream bypass flow exit (60) is formedbetween the fan nozzle sleeve (50) and the thrust reverser sleeve (82,84) when the fan nozzle sleeve (50) is in the extended position; and (d)a plurality of fan nozzle sleeve actuators (70) extending from thestationary forward nacelle portion to the fan nozzle sleeve areconfigured to selectively move the fan nozzle sleeve (50) between theforward position and the extended position, the fan nozzle sleeveactuators (70) being separate from and spaced apart from the thrustreverser sleeve actuators (90).
 2. A nacelle according to claim 1wherein the fan nozzle sleeve (50) comprises a first fan nozzle sleevesegment (54) disposed on a first side of the engine (10), and a secondfan nozzle sleeve segment (56) disposed on an opposed second side of theengine (10).
 3. A nacelle according to claim 1 further comprising atransverse bulkhead (110) on the forward nacelle portion, wherein thethrust reverser sleeve and the fan nozzle sleeve are movably connectedto the transverse bulkhead.
 4. A nacelle according to claim 3 furthercomprising: (a) a beam attached to the transverse bulkhead, the beamhaving at least a first guide track; (b) a first track bar attached tothe thrust reverser sleeve, the first track bar being slidably engagedin the beam guide track; (c) a second guide track attached to the thrustreverser sleeve; and (d) a second track bar attached to the fan nozzlesleeve, the second track bar being slidably engaged in the second guidetrack.
 5. A nacelle according to claim 4 wherein sliding movement of thefirst or second track bars is powered by at least one mechanical,electrical, hydraulic or pneumatic device.
 6. A nacelle for a turbofanaircraft engine (10) comprising: (a) a stationary forward nacelleportion (18) having an inlet end and an opposed rear end; (b) a thrustreverser (80) comprising: (i) a cascade array (88) disposed aft of therear end of the stationary forward nacelle portion; (ii) a translatingthrust reverser sleeve (82, 84) having a front edge and a trailing edge,the thrust reverser sleeve (82, 84) being movably disposed aft of therear end of the stationary forward nacelle portion (18), the thrustreverser sleeve (82, 84) being movable between a stowed position inwhich the front edge is proximate to the rear end of the stationaryforward nacelle portion (18) and the thrust reverser sleeve (82, 84)substantially covers the cascade array (88), and a deployed position inwhich the thrust reverser sleeve (82, 84) is disposed substantially aftof the cascade array (88) and the cascade array (88) is substantiallyuncovered; and (iii) at least one thrust reverser actuator (90)extending from the stationary forward nacelle portion (18) to the thrustreverser sleeve (82, 84), and being operable to selectively move thethrust reverser sleeve (82, 84) between the stowed position and thedeployed position; (c) a translating fan nozzle sleeve (50) having aforward edge, the fan nozzle sleeve (50) being movably disposed aft ofthe translating thrust reverser sleeve (82, 84), the fan nozzle sleeve(50) being movable between a forward position in which the forward edgeis proximate to the trailing edge of the thrust reverser sleeve (82,84), and an extended position in which an upstream bypass flow exit (60)is disposed between the forward edge of the fan nozzle sleeve (50) andthe trailing edge of the thrust reverser sleeve (82, 84); and (d) atleast one fan nozzle actuator (70) separate from and spaced apart fromthe thrust reverser actuator (90), the fan nozzle actuator (70) beingconfigured to selectively move the fan nozzle sleeve (50) between theforward position and the extended position.
 7. A nacelle according toclaim 6 wherein the translating thrust reverser sleeve (82, 84)comprises a first arcuate thrust reverser sleeve portion (82) and asecond arcuate thrust reverser sleeve portion (84), wherein at least onethrust reverser actuator (90) is operable to selectively move the firstthrust reverser sleeve portion (82) between the stowed position and thedeployed position, and wherein at least one thrust reverser actuator(90) is operable to selectively move the second thrust reverser sleeveportion (84) between the stowed position and the deployed position.
 8. Anacelle according to claim 6 wherein the translating fan nozzle sleeve(50) comprises a first arcuate fan nozzle sleeve portion (54) having afirst end and a second end, and a second arcuate fan nozzle sleeveportion (56) having a third end and a fourth end, wherein at least onefan nozzle actuator (70) is operable to selectively move the first fannozzle sleeve portion (54) between the forward position and the extendedposition, and wherein at least one fan nozzle actuator (70) is operableto selectively move the second thrust reverser sleeve portion (56)between the forward position and the extended position.
 9. A nacelleaccording to claim 8 further comprising a transverse bulkhead (110),wherein the first end of the first arcuate fan nozzle sleeve portion(54) and the third end of the second arcuate fan nozzle sleeve portion(56) are slidably connected an upper portion of the transverse bulkhead(110), and wherein the second end of the first arcuate fan nozzle sleeveportion (54) and the fourth end of the second arcuate fan nozzle sleeveportion (56) are slidably connected to a lower portion of the transversebulkhead (110).
 10. A nacelle according to claim 9 wherein each of thefirst, second, third and fourth ends of the respective first and secondfan nozzle sleeve portions (54, 56) is movably connected to thetransverse bulkhead (110) by a guide mechanism (102) comprising: (a) abeam (106) attached to and rearwardly extending from the transversebulkhead (110); (b) a first guide track (108) attached to the beam(106); (c) a first track bar (114) attached to the thrust reversersleeve (82, 84) and slidably engaged with the first guide track (108);(d) at least a second guide track (116) attached to the thrust reversersleeve (82, 84); and (e) a second track bar (120) slidably engaged withthe second guide track (116), the second track bar (120) being connectedto an end of a respective fan nozzle sleeve portion (54, 56).
 11. Anacelle according to claim 10 wherein sliding movement of the first orsecond track bars (114, 120) is powered by at least one mechanical,electrical, hydraulic or pneumatic device.
 12. A nacelle according toclaim 6 further comprising a plurality of spaced extendable guide tubes(104) axially extending between the thrust reverser sleeve (82, 84) andthe fan nozzle sleeve (50), the guide tubes (104) being configured topermit longitudinal translating movement of the fan nozzle sleeve (50),and to inhibit movement of the fan nozzle sleeve (50) in directions thatare transverse to the direction of the longitudinal translating movementof the fan nozzle sleeve (50).
 13. A nacelle according to claim 6wherein the fan nozzle actuator (70) is operable to move the fan nozzlesleeve (50) such that the forward edge of the fan nozzle sleeve is aselected distance from the trailing edge of the thrust reverser sleeve(82, 84) when the fan nozzle sleeve (50) is in the extended position,whereby a width of the upstream bypass flow exit (60) can be selectivelyvaried.
 14. A nacelle according to claim 6 further comprising a seal(130) disposed between the forward edge of the fan nozzle sleeve (50)and the trailing edge of the thrust reverser sleeve (82, 84), the seal(130) being configured to substantially block airflow between theforward edge of the fan nozzle sleeve (50) and the trailing edge of thethrust reverser sleeve (82, 84) when the fan nozzle sleeve (50) is inthe forward position.
 15. A nacelle for a turbofan aircraft engine, thenacelle comprising: (a) a stationary forward nacelle portion (18) havingan inlet end and an opposed aft end; (b) a translating fan nozzle sleeve(254, 256) having a forward edge, the fan nozzle sleeve (254, 256) beingmovably disposed aft of the forward nacelle portion (18), the fan nozzlesleeve (254, 256) being movable between a forward position, in which theforward edge is proximate to the aft end of the forward nacelle portion(18) with no cascade-type thrust reverser disposed therebetween, and oneor more extended positions in which an upstream bypass flow exit (260)is disposed between the forward edge of the fan nozzle sleeve (254, 256)and the aft end of the forward nacelle portion (18); and (c) at leastone fan nozzle actuator (270) extending from the stationary forwardnacelle portion (18) to the fan nozzle sleeve (254, 256), the fan nozzleactuator (270) being operable to selectively move the fan nozzle sleeve(254, 256) between the forward position and the extended position.
 16. Anacelle according to claim 15 wherein the translating fan nozzle sleeve(254, 256) comprises a first arcuate fan nozzle sleeve portion (254)having a first end and a second end, and a second arcuate fan nozzlesleeve portion (256) having a third end and a fourth end, wherein atleast one fan nozzle actuator (270) is operable to selectively move thefirst fan nozzle sleeve portion (254) to one or more positions betweenthe forward position and the extended position, and wherein at least onefan nozzle actuator (270) is operable to selectively move the second fannozzle sleeve portion (256) to one or more positions between the forwardposition and the extended position.
 17. A nacelle according to claim 16further comprising a transverse bulkhead (310), wherein the first end ofthe first arcuate fan nozzle sleeve portion (254) and the third end ofthe second arcuate fan nozzle sleeve portion (256) are slidably attachedto an upper portion of the transverse bulkhead (310), and wherein thesecond end of the first arcuate fan nozzle sleeve portion (254) and thefourth end of the second arcuate fan nozzle sleeve portion (256) areslidably attached to a lower portion of the transverse bulkhead (310).18. A nacelle according to claim 17 wherein each of the first, second,third and fourth ends of the respective first and second fan nozzlesleeve portions (254, 256) is movably connected to the transversebulkhead (310) by a guide mechanism (102) comprising: (a) a beam (106)attached to and rearwardly extending from the transverse bulkhead (310);(b) at least one guide track (108) attached to the beam (106); (c) atleast one track bar (114) slidably engaged with the guide track (108),and connected to an end of a respective fan nozzle sleeve portion (254,256).
 19. A nacelle according to claim 15 further comprising a pluralityof spaced extendable guide tubes (304) axially extending between theforward nacelle portion and the fan nozzle sleeve (254, 256), the guidetubes (304) being configured to permit longitudinal translating movementof the fan nozzle sleeve (254, 256), and to inhibit movement of the fannozzle sleeve (254, 256) in directions that are transverse to thedirection of the longitudinal translating movement of the fan nozzlesleeve (254, 256).
 20. A nacelle according to claim 15 wherein the fannozzle actuator (270) is operable to move the fan nozzle sleeve (254,256) such that the forward edge of the fan nozzle sleeve (254, 256) is aselected distance from the trailing edge of the forward nacelle portion(18) when the fan nozzle sleeve (254, 256) is in the extended position,thereby permitting a width of the upstream bypass flow exit (260) to beselectively varied.
 21. A nacelle according to claim 15 furthercomprising a blister fairing (320) extending along the aft end of theforward nacelle portion (18), the blister fairing (320) at leastpartially overlapping the forward edge of the translating fan nozzlesleeve (254, 256) when the fan nozzle sleeve (254, 256) is in theforward position.
 22. A nacelle according to claim 21 wherein a portionof the fan nozzle actuator (270) extends through an actuator opening inthe blister fairing (320) to the fan nozzle sleeve (254, 256), andfurther comprising an upstream fairing (324) on the blister fairing(320) at least partially shrouding the actuator opening, and adownstream fairing (328) at least partially shrouding the portion of thefan nozzle actuator (270).
 23. A nacelle according to claim 17 whereinan upstream portion (332) of a split beavertail fairing (330) on theforward stationary nacelle portion (18) at least partially shrouds aforward portion of a beam (106) rearwardly extending from the transversebulkhead (310), and wherein a downstream portion (334) of the splitbeavertail fairing (330) on the fan nozzle sleeve (254, 256) at leastpartially shrouds an aft portion of the beam (106), wherein the upstreamand downstream portions (332, 334) of the split beavertail fairing (330)combine to form a substantially continuous contoured external surfacewhen the translating fan nozzle sleeve (254, 256) is in the forwardposition.
 24. A nacelle for a turbofan aircraft engine comprising: (a) astationary forward nacelle portion (18) having an inlet end and anopposed rear end; (b) a thrust reverser comprising: (i) a cascade array(590) disposed aft of the rear end of the stationary forward nacelleportion (18); (ii) a translating thrust reverser sleeve (460) comprisingfirst and second thrust reverser sleeve segments (462, 464) each havinga front edge and a trailing edge, the thrust reverser sleeve segments(462, 464) being movably disposed aft of the rear end of the stationaryforward nacelle portion (18), each thrust reverser sleeve segment (462,464) being movable between a stowed position in which its front edge isproximate to the rear end of the stationary forward nacelle portion (18)and the thrust reverser sleeve segment (462, 464) substantially covers aportion of the cascade array (590), and a deployed position in which thethrust reverser sleeve segment (462, 464) is disposed substantially aftof the cascade array (590) and does not cover a substantial portion ofthe cascade array (590); and (iii) a plurality of thrust reverseractuators (464) operable to selectively move the thrust reverser sleevesegments (462, 464) between their stowed positions and their deployedpositions; (c) a translating fan nozzle sleeve (450) comprising firstand second fan nozzle sleeve segments (454, 456) each having a forwardedge, an upper end and a lower end, and being movably disposed aft ofthe translating thrust reverser sleeve (460), each fan nozzle sleevesegment (454, 456) being movable between a forward position in which theforward edge is proximate to the trailing edge of one of the thrustreverser sleeve segments (462, 464), and an extended position in whichan upstream bypass flow exit is disposed between the forward edge of thefan nozzle sleeve segment (454, 456) and the trailing edge of one of thethrust reverser sleeve segments (462, 464); and (d) a plurality of fannozzle sleeve actuators (470) that are separate from the thrust reverseractuators (464), at least one fan nozzle actuator (470) being locatedproximate to the upper end of each fan nozzle sleeve segment (454, 456)and at least one other fan nozzle actuator (470) being located proximateto the lower end of each fan nozzle sleeve segment (454, 456), the fannozzle actuators (470) being operable to selectively move the fan nozzlesleeve segments (454, 456) between their forward position and theirextended position.
 25. A nacelle according to claim 24 wherein the fannozzle actuators (470) extend from the thrust reverser sleeve (460) tothe fan nozzle sleeve (450).
 26. A nacelle according to claim 24 whereinthe fan nozzle actuators (470) extend from the forward nacelle portion(18) to the fan nozzle sleeve (450).
 27. A nacelle according to claim 24further comprising at least a first stabilizer (480) disposed betweenthe first thrust reverser sleeve segment (462) and the first fan nozzlesleeve segment (454), and at least a second stabilizer disposed betweenthe second thrust reverser sleeve segment (464) and the second fannozzle sleeve segment (456), the first and second stabilizers (480)being configured to permit translational movement between the thrustreverser sleeve segments (462, 464) and the fan nozzle sleeve segments(454, 456), and to substantially inhibit movement of the first andsecond fan nozzle sleeve segments (454, 456) in a direction that isnon-parallel to the translational movement between the thrust reversersleeve segments (462, 464) and the fan nozzle sleeve segments (454,456).
 28. A nacelle according to claim 24 further comprising: (a) a fannozzle sleeve drive mechanism (482); (b) a forward gear box (486)operably connected (485) to the fan nozzle sleeve drive mechanism (482),the forward gear box (486) being located forward of the translatingthrust reverser sleeve (462); (c) an aft gear box (488) positionedproximate to the front edge of the first fan nozzle sleeve segment(454); (d) a splined coupling (484) rotatably connecting the forwardgear box (486) to the aft gear box (488), the splined coupling (484)being axially extendable; and (e) at least one actuator cable (490)operably connecting at least a portion of the plurality of fan nozzleactuators (470) to the aft gear box (488); (f) whereby the fan nozzlesleeve drive mechanism (482) is operably coupled to at least a portionof the plurality of fan nozzle actuators (470) and is capable ofeffecting translation of the first fan nozzle sleeve segment (454)between its forward and extended positions.
 29. A nacelle according toclaim 24 further comprising an upper guide structure (500) slidablysupporting the upper ends of the first and second fan nozzle sleevesegments (454, 456), and a lower guide structure (500) slidablysupporting the lower ends of the first and second fan nozzle sleevesegments (454, 456).
 30. A nacelle according to claim 29 wherein theupper and lower guide structures (500) each comprise a beam (502) thatextends aft of the first and second translating thrust reverser sleeves(462), and a track bar (503) connected to one of the first and secondfan nozzle sleeve segments (454, 456), the track bar (503) beingslidably engaged with the beam (500).
 31. A nacelle according to claim30 further comprising a slider (504) attached to the track bar (503),and a screw shaft (506) engaged with the slider (504) and extendingbetween the slider (504) and an actuator gear box (508).
 32. A nacelleaccording to claim 28 wherein the fan nozzle sleeve drive mechanism(482) comprises a motor (516) coupled to a motor gear box (520), themotor gear box (520) being operably connected (485) to the forward gearbox (486), wherein selective rotation of the motor (516) causes rotationof the forward gear box (486) and actuation of the plurality of fannozzle sleeve actuators (470).
 33. A nacelle according to claim 32further comprising at least one controller (526/540) coupled to themotor (516), the controller (526/540) being configured to selectivelycontrol translation of the fan nozzle sleeve segments (454).
 34. Anacelle according to claim 24 wherein the cascade array comprises aplurality of substantially parallel longitudinally spaced vanes (790)having variable depths.
 35. A nacelle according to claim 34, wherein thedepths of the vanes (790) progressively decrease from a deepestforward-most vane to a shallowest aft-most vane.
 36. A nacelle accordingto claim 29 wherein the fan nozzle sleeve actuators (670) are positionedproximate to the upper and lower guide structures (700).